The invention relates to a security system for a solar module, more particularly for preventing unauthorized use by a consumer, a method for power transfer from a solar module to a consumer, a device for disabling power output of a solar module as well as a device for enabling power transfer from a solar module to a consumer.
Increasing environmental pollution is resulting in the use of regenerative energy, such as e.g. solar energy gaining in significance, it being particularly the development of ever more powerful solar modules that is making the use of regenerative solar energy possible in a broad scale of applications. It is especially in the case of small to medium power consumers needing to receive energy independently of a power grid that stand-alone solar modules have become popular due to their high performance, freedom from maintenance and simple application. However, since solar modules are put to use as a rule at locations which are difficult to monitor, such as e.g. the power supply for a traffic sign located remote from a power grid, or e.g. on the roof of a mobile home, it often occurs that the solar modules are stolen or made use of by an unauthorized consumer.
Current means usual for preventing unauthorized use or theft consist, as a rule, of a solid housing in conjunction with a strong lock. These means of security have the disadvantage, however, of being easily broken open by force and, in addition need to be configured heavy and solid for efficient security.
Known from German patent 36 41 230 C1 is an anti-theft system, more particularly for car radios. In this arrangement a first module A is sited in the car radio and a second module B at some other location in the car which is inaccessible. Module A regularly interrogates the security code in module B and compares it to a reference code memorized in module A. As long as both agree the radio remains enabled until the next interrogation. If there is no code agreement the radio is disabled, thus making it useless to steal the radio since it cannot function without the inaccessible module B.
Known from German patent 41 23 666 A1 is a security system for a mobile item of equipment prone to theft, such as a vehicle. In this case a code comparison is made between a code memorized in an ignition key and a code stored in a CPU in deciding whether devices critical to operation of the vehicle can be enabled.
The present invention is based on the object of providing security against unauthorized use of a solar module which although simple and cost-effective reliably prevents unauthorized use or theft.
This object is achieved in accordance with the present invention by a security system as set forth in claim 1, a method as set forth in claim 5, a disabling device as set forth in claim 8 and an enabling device as set forth in claim 14.
Preferred aspects read from the dependent claims.
The security system in accordance with the invention stops by advantageous ways and means the power output when the solar module-sited disabling device fails to receive a second signal via the power line within a first predefined time after having sent a first signal to the consumer-sited enabling device via the power line. Thus, if an unauthorized user having tapped into or stolen the solar module connects a consumer to the solar module, the solar module-sited disabling device sends the first signal and disables power output when it fails to receive the second signal within the first predefined time. The solar module is accordingly only of use to an authorized user in knowledge of the second signal and worthless to an unauthorized user having no knowledge of the second signal.
The invention permits a simple configuration of the security system which apart from the power line, necessary in any case, requires no connection between the solar module and the consumer.
In one advantageous aspect of the security system in accordance with the invention each first and second signal contains at least one pulse generated by disabling the power transfer via the power line.
In another advantageous aspect of the security system in accordance with the invention the solar module-sited disabling device and the consumer-sited enabling device each comprises a switching device for short-circuiting the power line to disable power transfer or to generate the aforementioned signals respectively.
This permits by advantageous ways and means a simple configuration of the security system when using the solar module with a battery charger including a charge regulator as the consumer operating on the shunt principle since in these charge regulators a short-circuiting device is already provided which can also be used by the security system, thus significantly simplifying circuiting.
The method in accordance with the invention permits by advantageous ways and means an integrated system for preventing unauthorized use of the solar module since no power transfer is possible without knowledge of a user authorization code or of the second signal.
The disabling device in accordance with the invention provides by advantageous ways and means security against unauthorized use or theft of the solar module in a system for simple and cost-effective production.
In one preferred embodiment the disabling device is configured integral with the solar module.
This arrangement ensures by advantageous ways and means that the disabling device in accordance with the invention cannot be defeated by tampering. The disabling device may be arranged, for example, as a slim-line assembly between the positive and negative leads in the laminate of the solar module or in or under the junction box where the leads are brought out directly from the laminate.
The enabling device in accordance with the invention comprises by advantageous ways and means a simple configuration for cost-effective production.